bin/rm/rm.c

   1 /*-
   2  * Copyright (c) 1990, 1993, 1994
   3  *      The Regents of the University of California.  All rights reserved.
   4  *
   5  * Redistribution and use in source and binary forms, with or without
   6  * modification, are permitted provided that the following conditions
   7  * are met:
   8  * 1. Redistributions of source code must retain the above copyright
   9  *    notice, this list of conditions and the following disclaimer.
  10  * 2. Redistributions in binary form must reproduce the above copyright
  11  *    notice, this list of conditions and the following disclaimer in the
  12  *    documentation and/or other materials provided with the distribution.
  13  * 4. Neither the name of the University nor the names of its contributors
  14  *    may be used to endorse or promote products derived from this software
  15  *    without specific prior written permission.
  16  *
  17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
  18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
  21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  27  * SUCH DAMAGE.
  28  */
  29
  30 #if 0
  31 #ifndef lint
  32 static const char copyright[] =
  33 "@(#) Copyright (c) 1990, 1993, 1994\n\
  34         The Regents of the University of California.  All rights reserved.\n";
  35 #endif /* not lint */
  36
  37 #ifndef lint
  38 static char sccsid[] = "@(#)rm.c        8.5 (Berkeley) 4/18/94";
  39 #endif /* not lint */
  40 #endif
  41 #include <sys/cdefs.h>
  42 __FBSDID("$FreeBSD$");
  43
  44 #include <sys/stat.h>
  45 #include <sys/param.h>
  46 #include <sys/mount.h>
  47
  48 #include <err.h>
  49 #include <errno.h>
  50 #include <fcntl.h>
  51 #include <fts.h>
  52 #include <grp.h>
  53 #include <pwd.h>
  54 #include <stdint.h>
  55 #include <stdio.h>
  56 #include <stdlib.h>
  57 #include <string.h>
  58 #include <sysexits.h>
  59 #include <unistd.h>
  60
  61 static int dflag, eval, fflag, iflag, Pflag, vflag, Wflag, stdin_ok;
  62 static int rflag, Iflag;
  63 static uid_t uid;
  64 static volatile sig_atomic_t info;
  65
  66 int     check(char *, char *, struct stat *);
  67 int     check2(char **);
  68 void    checkdot(char **);
  69 void    checkslash(char **);
  70 void    rm_file(char **);
  71 int     rm_overwrite(char *, struct stat *);
  72 void    rm_tree(char **);
  73 static void siginfo(int __unused);
  74 void    usage(void);
  75
  76 /*
  77  * rm --
  78  *      This rm is different from historic rm's, but is expected to match
  79  *      POSIX 1003.2 behavior.  The most visible difference is that -f
  80  *      has two specific effects now, ignore non-existent files and force
  81  *      file removal.
  82  */
  83 int
  84 main(int argc, char *argv[])
  85 {
  86         int ch;
  87         char *p;
  88
  89         /*
  90          * Test for the special case where the utility is called as
  91          * "unlink", for which the functionality provided is greatly
  92          * simplified.
  93          */
  94         if ((p = strrchr(argv[0], '/')) == NULL)
  95                 p = argv[0];
  96         else
  97                 ++p;
  98         if (strcmp(p, "unlink") == 0) {
  99                 while (getopt(argc, argv, "") != -1)
 100                         usage();
 101                 argc -= optind;
 102                 argv += optind;
 103                 if (argc != 1)
 104                         usage();
 105                 rm_file(&argv[0]);
 106                 exit(eval);
 107         }
 108
 109         Pflag = rflag = 0;
 110         while ((ch = getopt(argc, argv, "dfiIPRrvW")) != -1)
 111                 switch(ch) {
 112                 case 'd':
 113                         dflag = 1;
 114                         break;
 115                 case 'f':
 116                         fflag = 1;
 117                         iflag = 0;
 118                         break;
 119                 case 'i':
 120                         fflag = 0;
 121                         iflag = 1;
 122                         break;
 123                 case 'I':
 124                         Iflag = 1;
 125                         break;
 126                 case 'P':
 127                         Pflag = 1;
 128                         break;
 129                 case 'R':
 130                 case 'r':                       /* Compatibility. */
 131                         rflag = 1;
 132                         break;
 133                 case 'v':
 134                         vflag = 1;
 135                         break;
 136                 case 'W':
 137                         Wflag = 1;
 138                         break;
 139                 default:
 140                         usage();
 141                 }
 142         argc -= optind;
 143         argv += optind;
 144
 145         if (argc < 1) {
 146                 if (fflag)
 147                         return (0);
 148                 usage();
 149         }
 150
 151         checkdot(argv);
 152         if (getenv("POSIXLY_CORRECT") == NULL)
 153                 checkslash(argv);
 154         uid = geteuid();
 155
 156         (void)signal(SIGINFO, siginfo);
 157         if (*argv) {
 158                 stdin_ok = isatty(STDIN_FILENO);
 159
 160                 if (Iflag) {
 161                         if (check2(argv) == 0)
 162                                 exit (1);
 163                 }
 164                 if (rflag)
 165                         rm_tree(argv);
 166                 else
 167                         rm_file(argv);
 168         }
 169
 170         exit (eval);
 171 }
 172
 173 void
 174 rm_tree(char **argv)
 175 {
 176         FTS *fts;
 177         FTSENT *p;
 178         int needstat;
 179         int flags;
 180         int rval;
 181
 182         /*
 183          * Remove a file hierarchy.  If forcing removal (-f), or interactive
 184          * (-i) or can't ask anyway (stdin_ok), don't stat the file.
 185          */
 186         needstat = !uid || (!fflag && !iflag && stdin_ok);
 187
 188         /*
 189          * If the -i option is specified, the user can skip on the pre-order
 190          * visit.  The fts_number field flags skipped directories.
 191          */
 192 #define SKIPPED 1
 193
 194         flags = FTS_PHYSICAL;
 195         if (!needstat)
 196                 flags |= FTS_NOSTAT;
 197         if (Wflag)
 198                 flags |= FTS_WHITEOUT;
 199         if (!(fts = fts_open(argv, flags, NULL))) {
 200                 if (fflag && errno == ENOENT)
 201                         return;
 202                 err(1, "fts_open");
 203         }
 204         while ((p = fts_read(fts)) != NULL) {
 205                 switch (p->fts_info) {
 206                 case FTS_DNR:
 207                         if (!fflag || p->fts_errno != ENOENT) {
 208                                 warnx("%s: %s",
 209                                     p->fts_path, strerror(p->fts_errno));
 210                                 eval = 1;
 211                         }
 212                         continue;
 213                 case FTS_ERR:
 214                         errx(1, "%s: %s", p->fts_path, strerror(p->fts_errno));
 215                 case FTS_NS:
 216                         /*
 217                          * Assume that since fts_read() couldn't stat the
 218                          * file, it can't be unlinked.
 219                          */
 220                         if (!needstat)
 221                                 break;
 222                         if (!fflag || p->fts_errno != ENOENT) {
 223                                 warnx("%s: %s",
 224                                     p->fts_path, strerror(p->fts_errno));
 225                                 eval = 1;
 226                         }
 227                         continue;
 228                 case FTS_D:
 229                         /* Pre-order: give user chance to skip. */
 230                         if (!fflag && !check(p->fts_path, p->fts_accpath,
 231                             p->fts_statp)) {
 232                                 (void)fts_set(fts, p, FTS_SKIP);
 233                                 p->fts_number = SKIPPED;
 234                         }
 235                         else if (!uid &&
 236                                  (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 237                                  !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 238                                  lchflags(p->fts_accpath,
 239                                          p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE)) < 0)
 240                                 goto err;
 241                         continue;
 242                 case FTS_DP:
 243                         /* Post-order: see if user skipped. */
 244                         if (p->fts_number == SKIPPED)
 245                                 continue;
 246                         break;
 247                 default:
 248                         if (!fflag &&
 249                             !check(p->fts_path, p->fts_accpath, p->fts_statp))
 250                                 continue;
 251                 }
 252
 253                 rval = 0;
 254                 if (!uid &&
 255                     (p->fts_statp->st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 256                     !(p->fts_statp->st_flags & (SF_APPEND|SF_IMMUTABLE)))
 257                         rval = lchflags(p->fts_accpath,
 258                                        p->fts_statp->st_flags &= ~(UF_APPEND|UF_IMMUTABLE));
 259                 if (rval == 0) {
 260                         /*
 261                          * If we can't read or search the directory, may still be
 262                          * able to remove it.  Don't print out the un{read,search}able
 263                          * message unless the remove fails.
 264                          */
 265                         switch (p->fts_info) {
 266                         case FTS_DP:
 267                         case FTS_DNR:
 268                                 rval = rmdir(p->fts_accpath);
 269                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 270                                         if (rval == 0 && vflag)
 271                                                 (void)printf("%s\n",
 272                                                     p->fts_path);
 273                                         if (rval == 0 && info) {
 274                                                 info = 0;
 275                                                 (void)printf("%s\n",
 276                                                     p->fts_path);
 277                                         }
 278                                         continue;
 279                                 }
 280                                 break;
 281
 282                         case FTS_W:
 283                                 rval = undelete(p->fts_accpath);
 284                                 if (rval == 0 && (fflag && errno == ENOENT)) {
 285                                         if (vflag)
 286                                                 (void)printf("%s\n",
 287                                                     p->fts_path);
 288                                         if (info) {
 289                                                 info = 0;
 290                                                 (void)printf("%s\n",
 291                                                     p->fts_path);
 292                                         }
 293                                         continue;
 294                                 }
 295                                 break;
 296
 297                         case FTS_NS:
 298                                 /*
 299                                  * Assume that since fts_read() couldn't stat
 300                                  * the file, it can't be unlinked.
 301                                  */
 302                                 if (fflag)
 303                                         continue;
 304                                 /* FALLTHROUGH */
 305
 306                         case FTS_F:
 307                         case FTS_NSOK:
 308                                 if (Pflag)
 309                                         if (!rm_overwrite(p->fts_accpath, p->fts_info ==
 310                                             FTS_NSOK ? NULL : p->fts_statp))
 311                                                 continue;
 312                                 /* FALLTHROUGH */
 313
 314                         default:
 315                                 rval = unlink(p->fts_accpath);
 316                                 if (rval == 0 || (fflag && errno == ENOENT)) {
 317                                         if (rval == 0 && vflag)
 318                                                 (void)printf("%s\n",
 319                                                     p->fts_path);
 320                                         if (rval == 0 && info) {
 321                                                 info = 0;
 322                                                 (void)printf("%s\n",
 323                                                     p->fts_path);
 324                                         }
 325                                         continue;
 326                                 }
 327                         }
 328                 }
 329 err:
 330                 warn("%s", p->fts_path);
 331                 eval = 1;
 332         }
 333         if (errno)
 334                 err(1, "fts_read");
 335         fts_close(fts);
 336 }
 337
 338 void
 339 rm_file(char **argv)
 340 {
 341         struct stat sb;
 342         int rval;
 343         char *f;
 344
 345         /*
 346          * Remove a file.  POSIX 1003.2 states that, by default, attempting
 347          * to remove a directory is an error, so must always stat the file.
 348          */
 349         while ((f = *argv++) != NULL) {
 350                 /* Assume if can't stat the file, can't unlink it. */
 351                 if (lstat(f, &sb)) {
 352                         if (Wflag) {
 353                                 sb.st_mode = S_IFWHT|S_IWUSR|S_IRUSR;
 354                         } else {
 355                                 if (!fflag || errno != ENOENT) {
 356                                         warn("%s", f);
 357                                         eval = 1;
 358                                 }
 359                                 continue;
 360                         }
 361                 } else if (Wflag) {
 362                         warnx("%s: %s", f, strerror(EEXIST));
 363                         eval = 1;
 364                         continue;
 365                 }
 366
 367                 if (S_ISDIR(sb.st_mode) && !dflag) {
 368                         warnx("%s: is a directory", f);
 369                         eval = 1;
 370                         continue;
 371                 }
 372                 if (!fflag && !S_ISWHT(sb.st_mode) && !check(f, f, &sb))
 373                         continue;
 374                 rval = 0;
 375                 if (!uid && !S_ISWHT(sb.st_mode) &&
 376                     (sb.st_flags & (UF_APPEND|UF_IMMUTABLE)) &&
 377                     !(sb.st_flags & (SF_APPEND|SF_IMMUTABLE)))
 378                         rval = lchflags(f, sb.st_flags & ~(UF_APPEND|UF_IMMUTABLE));
 379                 if (rval == 0) {
 380                         if (S_ISWHT(sb.st_mode))
 381                                 rval = undelete(f);
 382                         else if (S_ISDIR(sb.st_mode))
 383                                 rval = rmdir(f);
 384                         else {
 385                                 if (Pflag)
 386                                         if (!rm_overwrite(f, &sb))
 387                                                 continue;
 388                                 rval = unlink(f);
 389                         }
 390                 }
 391                 if (rval && (!fflag || errno != ENOENT)) {
 392                         warn("%s", f);
 393                         eval = 1;
 394                 }
 395                 if (vflag && rval == 0)
 396                         (void)printf("%s\n", f);
 397                 if (info && rval == 0) {
 398                         info = 0;
 399                         (void)printf("%s\n", f);
 400                 }
 401         }
 402 }
 403
 404 /*
 405  * rm_overwrite --
 406  *      Overwrite the file 3 times with varying bit patterns.
 407  *
 408  * XXX
 409  * This is a cheap way to *really* delete files.  Note that only regular
 410  * files are deleted, directories (and therefore names) will remain.
 411  * Also, this assumes a fixed-block file system (like FFS, or a V7 or a
 412  * System V file system).  In a logging or COW file system, you'll have to
 413  * have kernel support.
 414  */
 415 int
 416 rm_overwrite(char *file, struct stat *sbp)
 417 {
 418         struct stat sb, sb2;
 419         struct statfs fsb;
 420         off_t len;
 421         int bsize, fd, wlen;
 422         char *buf = NULL;
 423
 424         fd = -1;
 425         if (sbp == NULL) {
 426                 if (lstat(file, &sb))
 427                         goto err;
 428                 sbp = &sb;
 429         }
 430         if (!S_ISREG(sbp->st_mode))
 431                 return (1);
 432         if (sbp->st_nlink > 1 && !fflag) {
 433                 warnx("%s (inode %ju): not overwritten due to multiple links",
 434                     file, (uintmax_t)sbp->st_ino);
 435                 return (0);
 436         }
 437         if ((fd = open(file, O_WRONLY|O_NONBLOCK|O_NOFOLLOW, 0)) == -1)
 438                 goto err;
 439         if (fstat(fd, &sb2))
 440                 goto err;
 441         if (sb2.st_dev != sbp->st_dev || sb2.st_ino != sbp->st_ino ||
 442             !S_ISREG(sb2.st_mode)) {
 443                 errno = EPERM;
 444                 goto err;
 445         }
 446         if (fstatfs(fd, &fsb) == -1)
 447                 goto err;
 448         bsize = MAX(fsb.f_iosize, 1024);
 449         if ((buf = malloc(bsize)) == NULL)
 450                 err(1, "%s: malloc", file);
 451
 452 #define PASS(byte) {                                                    \
 453         memset(buf, byte, bsize);                                       \
 454         for (len = sbp->st_size; len > 0; len -= wlen) {                \
 455                 wlen = len < bsize ? len : bsize;                       \
 456                 if (write(fd, buf, wlen) != wlen)                       \
 457                         goto err;                                       \
 458         }                                                               \
 459 }
 460         PASS(0xff);
 461         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 462                 goto err;
 463         PASS(0x00);
 464         if (fsync(fd) || lseek(fd, (off_t)0, SEEK_SET))
 465                 goto err;
 466         PASS(0xff);
 467         if (!fsync(fd) && !close(fd)) {
 468                 free(buf);
 469                 return (1);
 470         }
 471
 472 err:    eval = 1;
 473         if (buf)
 474                 free(buf);
 475         if (fd != -1)
 476                 close(fd);
 477         warn("%s", file);
 478         return (0);
 479 }
 480
 481
 482 int
 483 check(char *path, char *name, struct stat *sp)
 484 {
 485         int ch, first;
 486         char modep[15], *flagsp;
 487
 488         /* Check -i first. */
 489         if (iflag)
 490                 (void)fprintf(stderr, "remove %s? ", path);
 491         else {
 492                 /*
 493                  * If it's not a symbolic link and it's unwritable and we're
 494                  * talking to a terminal, ask.  Symbolic links are excluded
 495                  * because their permissions are meaningless.  Check stdin_ok
 496                  * first because we may not have stat'ed the file.
 497                  */
 498                 if (!stdin_ok || S_ISLNK(sp->st_mode) ||
 499                     (!access(name, W_OK) &&
 500                     !(sp->st_flags & (SF_APPEND|SF_IMMUTABLE)) &&
 501                     (!(sp->st_flags & (UF_APPEND|UF_IMMUTABLE)) || !uid)))
 502                         return (1);
 503                 strmode(sp->st_mode, modep);
 504                 if ((flagsp = fflagstostr(sp->st_flags)) == NULL)
 505                         err(1, "fflagstostr");
 506                 if (Pflag)
 507                         errx(1,
 508                             "%s: -P was specified, but file is not writable",
 509                             path);
 510                 (void)fprintf(stderr, "override %s%s%s/%s %s%sfor %s? ",
 511                     modep + 1, modep[9] == ' ' ? "" : " ",
 512                     user_from_uid(sp->st_uid, 0),
 513                     group_from_gid(sp->st_gid, 0),
 514                     *flagsp ? flagsp : "", *flagsp ? " " : "",
 515                     path);
 516                 free(flagsp);
 517         }
 518         (void)fflush(stderr);
 519
 520         first = ch = getchar();
 521         while (ch != '\n' && ch != EOF)
 522                 ch = getchar();
 523         return (first == 'y' || first == 'Y');
 524 }
 525
 526 #define ISSLASH(a)      ((a)[0] == '/' && (a)[1] == '\0')
 527 void
 528 checkslash(char **argv)
 529 {
 530         char **t, **u;
 531         int complained;
 532
 533         complained = 0;
 534         for (t = argv; *t;) {
 535                 if (ISSLASH(*t)) {
 536                         if (!complained++)
 537                                 warnx("\"/\" may not be removed");
 538                         eval = 1;
 539                         for (u = t; u[0] != NULL; ++u)
 540                                 u[0] = u[1];
 541                 } else {
 542                         ++t;
 543                 }
 544         }
 545 }
 546
 547 int
 548 check2(char **argv)
 549 {
 550         struct stat st;
 551         int first;
 552         int ch;
 553         int fcount = 0;
 554         int dcount = 0;
 555         int i;
 556         const char *dname = NULL;
 557
 558         for (i = 0; argv[i]; ++i) {
 559                 if (lstat(argv[i], &st) == 0) {
 560                         if (S_ISDIR(st.st_mode)) {
 561                                 ++dcount;
 562                                 dname = argv[i];    /* only used if 1 dir */
 563                         } else {
 564                                 ++fcount;
 565                         }
 566                 }
 567         }
 568         first = 0;
 569         while (first != 'n' && first != 'N' && first != 'y' && first != 'Y') {
 570                 if (dcount && rflag) {
 571                         fprintf(stderr, "recursively remove");
 572                         if (dcount == 1)
 573                                 fprintf(stderr, " %s", dname);
 574                         else
 575                                 fprintf(stderr, " %d dirs", dcount);
 576                         if (fcount == 1)
 577                                 fprintf(stderr, " and 1 file");
 578                         else if (fcount > 1)
 579                                 fprintf(stderr, " and %d files", fcount);
 580                 } else if (dcount + fcount > 3) {
 581                         fprintf(stderr, "remove %d files", dcount + fcount);
 582                 } else {
 583                         return(1);
 584                 }
 585                 fprintf(stderr, "? ");
 586                 fflush(stderr);
 587
 588                 first = ch = getchar();
 589                 while (ch != '\n' && ch != EOF)
 590                         ch = getchar();
 591                 if (ch == EOF)
 592                         break;
 593         }
 594         return (first == 'y' || first == 'Y');
 595 }
 596
 597 #define ISDOT(a)        ((a)[0] == '.' && (!(a)[1] || ((a)[1] == '.' && !(a)[2])))
 598 void
 599 checkdot(char **argv)
 600 {
 601         char *p, **save, **t;
 602         int complained;
 603
 604         complained = 0;
 605         for (t = argv; *t;) {
 606                 if ((p = strrchr(*t, '/')) != NULL)
 607                         ++p;
 608                 else
 609                         p = *t;
 610                 if (ISDOT(p)) {
 611                         if (!complained++)
 612                                 warnx("\".\" and \"..\" may not be removed");
 613                         eval = 1;
 614                         for (save = t; (t[0] = t[1]) != NULL; ++t)
 615                                 continue;
 616                         t = save;
 617                 } else
 618                         ++t;
 619         }
 620 }
 621
 622 void
 623 usage(void)
 624 {
 625
 626         (void)fprintf(stderr, "%s\n%s\n",
 627             "usage: rm [-f | -i] [-dIPRrvW] file ...",
 628             "       unlink file");
 629         exit(EX_USAGE);
 630 }
 631
 632 static void
 633 siginfo(int sig __unused)
 634 {
 635
 636         info = 1;
 637 }